* {margin: 0; padding: 0;}
#main {
    position: relative;
}
.box { /*每个图片之间的距离*/
    padding: 15px 0 0 15px;
    float: left;
}
.pic {
    padding: 15px;
    border: 1px solid #ccc;
    box-shadow: 0 0 5px #ccc;
    border-radius: 5px;
}
.pic img { /*所有图片等宽不等高*/
    width: 245px;
    heigth: auto
}